Combined usmle step 3 uworld
practice test 2, USMLE Step3
UWSA2 Notes, UWSA#2
Comprehensive Questions and
Solutions Graded A+
3 yo M has a 8 day hx of 3-4 daily episodes of soft, *foul-smelling diarrhea*. Increased belching
& Flatus, decreased appetite but drinks liquids without difficulty. 6 yr old sister has same sx.
Fam went on cruise to Mexico last month so he tried new foods and went swimming at
beach&in cruise ship pool. Went on wkd camping trip 3 wks ago and ate the fresh fish. After
vacation, he went back to reg diet fruits, veggies 7 meats. P 108, hyperactive bowel sounds.
negative stool occult blood. CAUSE of sx? - Answer: *giardia lamblia*
-greasy, foul-smelling diarrhea, bloating, flatus/belching, weight loss
-transmitted thru *fecal-oral route* or thru *contaminated food or water*
-ingestion of unfiltered water while *camping* or hiking
--drinking, swimming or consuming food from contaminated water
-sx DON't present ASAP b/c takes time for cysts to mature into trophozoites in host intestines
-tx: *metronidazole*
norovirus - Answer: -causes viral gastroenteritis
-*cruise-ship* outbreaks
-BRIEF duration: resolves within days
,-*VOMITING more common*rota
rotavirus - Answer: *watery diarrhea* in kids age 2 and under
-within 1-2 DAYS of exposure
-also emesis, abd pain
This child with fever, emesis, profuse watery diarrhea, and hyperactive bowel sounds likely has
viral gastroenteritis. Rotavirus is one of the most common causes of viral gastroenteritis in
children worldwide, particularly at age <2. It usually occurs during winter and can spread rapidly
in schools or day care facilities.
Since the introduction of widespread rotavirus vaccination, the incidence of rotavirus-related
hospitalization has decreased drastically. Therefore, this oral, live-attenuated vaccine is
recommended for all healthy infants. The vaccine is generally well tolerated and any side effects
(eg, fussiness, low fever) are usually mild. The vaccine is associated with a slightly increased risk
of intussusception; however, this potential effect is rare and much less likely than the risk of
severe rotavirus gastroenteritis in unvaccinated children.
meta-analysis - Answer: -combines results of *several studies* to *increase statistical power*
thru an *increased sample size*
-ideally, the results are the same as produced by single study w/larger sample size
-BUT *increase in statistical power may lead to *statistically SIGNIFICANT* effect sizes that
maybe *CLINICALLY IRRELEVANT*=detects a very small effect(eg risk ratio)--not practical
---also, *validity depends on the design*-metanalysis isn't always more valid than other study
designs
cephalohematoma vs caput succedaneum - Answer: cephalohematoma: DOESN'T cross suture
lines & resolves within WEEKS, *can lead to jaundice* b/c RBC breakdown&Calcification after
resolution-located UNDER periosteum
,Caput succedaneum: like a CAP crosses suture lines&resolves DAYS after birth-serosanuineous
fluid collection above periosteum/beneath scalp
subgaleal hemorrhage - Answer: -bleeding under galea aponeurotica
-fatal complication of vacuum-assisted deliveries
-rapidly expanding swelling leading to hypovolemic shock from blood loss
2 week old girl has *asymmetric gluteal skinfolds&increased # thigh creases on right>left*. what
else would be found? - Answer: *Apparent leg-length discrepancy* when pt lies supine w/knees
flexed: affected leg looks shorter(Galeazzi test)
DX: developmental dysplasia of hip
-abnormal development of hip joint tht prevents femoral head from sitting properly in
acetabulum
-RF: *females, breech position, FH DDH, excessively tight swaddling*
-instability during attempted dislocation&reduction if palpable clunk heard (Barlow and Ortolani
maneuvers)
who has asymmetric moro reflex? - Answer: erb palsy (seen in large for gestational age infants)
who has sacral dimple? - Answer: neural tube defect (myelomeningocele)
what's the next step after u/s shows dislocated right hip w/flat acetabulum and positive barlow
and ortolani tests? - Answer: *Consult orthopedic surgeon*
--when ID within first 6 months of life, treat by maintaining hip in *flexed&abducted position in
Pavlik harness for 3 months*
-when hip extension & adduction are limited, the dislocated hip is reduced and/or stabilized and
normal acetabular development is promoted
--monitor pavlik harness closely by orthopedic surgeon b/c associated risks( avascular necrosis,
femoral nerve palsy) w/excessive hip flexion & abduction
, >hip radiograph if >4 months old
prognosis for development dysplasia of hip - Answer: *most infants who are treated early have
no long-term sequelae*
-the need for surgical correction for DDH correlates w/increased age at diagnosis: <5% of pts dx
& treated w/pavlik harness in early infancy require surgery
vestibular neuritis(labyrinthitis) - Answer: -*single episode* of severe vertigo that can last for
days & is self-limited
-*labyrinthitis when associated w/unilateral hearing loss*
-normal MRI
-after viral infection
-feeling of imabalnce and unsteady gait
-*positive head-thrust test*:pt focuses on examiner's nose while examiner quickly rotates their
head 10-15 degrees to the side; normally the eyes remain fixed on the target but in pt
w/peripheral vestibular d/o, the eyes initially rotate w/the head before voluntarily redirecting
back to the target (corrective saccade)
first line treatment for MDD w/psychotic features (esp if severely depressed, psychotic, suicidal,
refusing to eat &Drink) - Answer: ECT!!!
-not mirtazapine -its not enuf alone to treat MDD w/psychotic features -combine it
w/antipsychotic
17 yo girl has 3 week hx of rhinorrhea, paroyxyms of sneezing, nasal congestion, facial itching &
Develops similar sx each spring. This yr, sx are more severe than usual &persistent. Pale nasal
mucosa. Started on the most effective single treatment but what's a complication? - Answer:
*epistaxis*
dx: allergic rhinitis
tx: *intranasal corticosteroids* (not antihistamines)-fluticasone, mometasone, budesonide
practice test 2, USMLE Step3
UWSA2 Notes, UWSA#2
Comprehensive Questions and
Solutions Graded A+
3 yo M has a 8 day hx of 3-4 daily episodes of soft, *foul-smelling diarrhea*. Increased belching
& Flatus, decreased appetite but drinks liquids without difficulty. 6 yr old sister has same sx.
Fam went on cruise to Mexico last month so he tried new foods and went swimming at
beach&in cruise ship pool. Went on wkd camping trip 3 wks ago and ate the fresh fish. After
vacation, he went back to reg diet fruits, veggies 7 meats. P 108, hyperactive bowel sounds.
negative stool occult blood. CAUSE of sx? - Answer: *giardia lamblia*
-greasy, foul-smelling diarrhea, bloating, flatus/belching, weight loss
-transmitted thru *fecal-oral route* or thru *contaminated food or water*
-ingestion of unfiltered water while *camping* or hiking
--drinking, swimming or consuming food from contaminated water
-sx DON't present ASAP b/c takes time for cysts to mature into trophozoites in host intestines
-tx: *metronidazole*
norovirus - Answer: -causes viral gastroenteritis
-*cruise-ship* outbreaks
-BRIEF duration: resolves within days
,-*VOMITING more common*rota
rotavirus - Answer: *watery diarrhea* in kids age 2 and under
-within 1-2 DAYS of exposure
-also emesis, abd pain
This child with fever, emesis, profuse watery diarrhea, and hyperactive bowel sounds likely has
viral gastroenteritis. Rotavirus is one of the most common causes of viral gastroenteritis in
children worldwide, particularly at age <2. It usually occurs during winter and can spread rapidly
in schools or day care facilities.
Since the introduction of widespread rotavirus vaccination, the incidence of rotavirus-related
hospitalization has decreased drastically. Therefore, this oral, live-attenuated vaccine is
recommended for all healthy infants. The vaccine is generally well tolerated and any side effects
(eg, fussiness, low fever) are usually mild. The vaccine is associated with a slightly increased risk
of intussusception; however, this potential effect is rare and much less likely than the risk of
severe rotavirus gastroenteritis in unvaccinated children.
meta-analysis - Answer: -combines results of *several studies* to *increase statistical power*
thru an *increased sample size*
-ideally, the results are the same as produced by single study w/larger sample size
-BUT *increase in statistical power may lead to *statistically SIGNIFICANT* effect sizes that
maybe *CLINICALLY IRRELEVANT*=detects a very small effect(eg risk ratio)--not practical
---also, *validity depends on the design*-metanalysis isn't always more valid than other study
designs
cephalohematoma vs caput succedaneum - Answer: cephalohematoma: DOESN'T cross suture
lines & resolves within WEEKS, *can lead to jaundice* b/c RBC breakdown&Calcification after
resolution-located UNDER periosteum
,Caput succedaneum: like a CAP crosses suture lines&resolves DAYS after birth-serosanuineous
fluid collection above periosteum/beneath scalp
subgaleal hemorrhage - Answer: -bleeding under galea aponeurotica
-fatal complication of vacuum-assisted deliveries
-rapidly expanding swelling leading to hypovolemic shock from blood loss
2 week old girl has *asymmetric gluteal skinfolds&increased # thigh creases on right>left*. what
else would be found? - Answer: *Apparent leg-length discrepancy* when pt lies supine w/knees
flexed: affected leg looks shorter(Galeazzi test)
DX: developmental dysplasia of hip
-abnormal development of hip joint tht prevents femoral head from sitting properly in
acetabulum
-RF: *females, breech position, FH DDH, excessively tight swaddling*
-instability during attempted dislocation&reduction if palpable clunk heard (Barlow and Ortolani
maneuvers)
who has asymmetric moro reflex? - Answer: erb palsy (seen in large for gestational age infants)
who has sacral dimple? - Answer: neural tube defect (myelomeningocele)
what's the next step after u/s shows dislocated right hip w/flat acetabulum and positive barlow
and ortolani tests? - Answer: *Consult orthopedic surgeon*
--when ID within first 6 months of life, treat by maintaining hip in *flexed&abducted position in
Pavlik harness for 3 months*
-when hip extension & adduction are limited, the dislocated hip is reduced and/or stabilized and
normal acetabular development is promoted
--monitor pavlik harness closely by orthopedic surgeon b/c associated risks( avascular necrosis,
femoral nerve palsy) w/excessive hip flexion & abduction
, >hip radiograph if >4 months old
prognosis for development dysplasia of hip - Answer: *most infants who are treated early have
no long-term sequelae*
-the need for surgical correction for DDH correlates w/increased age at diagnosis: <5% of pts dx
& treated w/pavlik harness in early infancy require surgery
vestibular neuritis(labyrinthitis) - Answer: -*single episode* of severe vertigo that can last for
days & is self-limited
-*labyrinthitis when associated w/unilateral hearing loss*
-normal MRI
-after viral infection
-feeling of imabalnce and unsteady gait
-*positive head-thrust test*:pt focuses on examiner's nose while examiner quickly rotates their
head 10-15 degrees to the side; normally the eyes remain fixed on the target but in pt
w/peripheral vestibular d/o, the eyes initially rotate w/the head before voluntarily redirecting
back to the target (corrective saccade)
first line treatment for MDD w/psychotic features (esp if severely depressed, psychotic, suicidal,
refusing to eat &Drink) - Answer: ECT!!!
-not mirtazapine -its not enuf alone to treat MDD w/psychotic features -combine it
w/antipsychotic
17 yo girl has 3 week hx of rhinorrhea, paroyxyms of sneezing, nasal congestion, facial itching &
Develops similar sx each spring. This yr, sx are more severe than usual &persistent. Pale nasal
mucosa. Started on the most effective single treatment but what's a complication? - Answer:
*epistaxis*
dx: allergic rhinitis
tx: *intranasal corticosteroids* (not antihistamines)-fluticasone, mometasone, budesonide
